[quote=paramount]
6 channels
10 loudspeakers
• 2 treble loudspeakers, front 26 mm
• 2 mid-range loudspeakers, front 100 mm
• 2 bass loudspeakers, 217 mm
• 2 mid-range loudspeakers, rear, 100 mm
• 2 treble loudspeakers, rear 26 mm
Bandwidth: 40 Hz to 20.000 Hz
Max. acoustic pressure: 104 dB
Amplifier power:
2 x 40 W (2 Ω) Bass
4 x 25 W (2 Ω)[/quote]
Those are the kinds of number I was expecting. Although the mid drivers at only 4″ is a little lacking. The amps are driving those speakers at 2 Ω, like all stock amps I’ve seen. If you look into amps, you’ll notice the Wattage output increases as the impedance decreases (i.e. the output will be higher at 2 Ω vs 4 Ω). The higher the impedance, the cleaner the power, which would create cleaner sounds. Especially at higher dB.

A standard aftermarket 5 channel amps like this one: http://www.bostonacoustics.com/GTA-1005-P613.aspx out puts 4 x 50W (at 4 Ω) or 4 x 80W (at 2 Ω). The subwoofer channel outputs at 2 x 160W or 1 x 250W (at 4 Ω).

Here’s a decent aftermarket subwoofer: http://www.bostonacoustics.com/G310-P566.aspx
It’s rated at 350W RMS, which means it can be driven constantly at 350W. RMS power rating is always lower than peak power. It wouldn’t surprise me if these subs can handle 500W peak. If you look at the magnets on these subwoofers vs the stock 8″, you’ll see what I mean. To drive a tight deep sound, you need big magnets. There’s no way around it.

Here’s a decent set of aftermarket components: http://www.bostonacoustics.com/Pro60SE-P601.aspx
Although they’re rated at 50Hz-22kHz frequency response, I wouldn’t want to drive these much lower than 120Hz. I keep the <120Hz dedicated to the subwoofers.

My point is, 2 x 40W for the 8" sub and 4 x 25W for mids/highs are quite lacking in my book. If you have a chance, take that Eagle CD to a store that sell aftermarket stereos (like Best Buy) and listen to Hotel California with a high end systems and let me know if you can tell the difference between the stock BMW's sound system and the aftermarket one.